> a nicely portable fuel not subject to transmission losses

Transporting hydrogen is pretty lossy, mostly because of its bulk. Compression or liquefaction for transfer (and storage-- keeping liquid hydrogen stored requires you to either continuously input energy to refrigerate it, or continuously let some of it boil away) will eat 30-40% of the energy in the hydrogen you started with. And there's no such thing as "not subject to transmission losses" in general. Pipelines have losses just like the grid-- fluids don't just move to where you want them to go on their own. Pumping stations are required and leaks are inevitable.

Average transmission and distribution loss on the US power grid is about 5%.

That's not to say there aren't going to be some uses for hydrogen-- but as a general rule, if what you're doing can be done via the grid or another storage option, hydrogen seems like it will have a hard time competing.